The goal of this proposal is to improve and maintain our software DtiStudio. There are three main functions in this software. First, It reads and process data for diffusion tensor Imaging (DTI), a modern technology of magnetic resonance imaging (MRI). Unlike other MRI techniques, various types of images from DTI can be obtained only after complicated calculations and DTI data processing tools are not readily available. Second, the software provides interface for data analysis and quantification. Unlike conventional MRI, DTI contains 6 parameters in each pixel. Conventional MRI analysis software, therefore, is not always applicable for DTI data. Third, it allows 3D tract reconstruction of white matter tracts. This is again not a technique that can be readily developed by average users. On the other hand, DTI is becoming an important tool for various types of brain researches. The data acquisition scheme is now available in commercial MRI scanners and DTI data can be obtained easily as routine clinical practices. Needs for DTI data processing and analysis software is rapidly growing. Our DtiStudio now has approximately 3,000 registered users and the number is growing with an average rate of 40 users I month. The work load for software maintenance and user support is steadfastly growing while simultaneously new functions of the software are rapidly evolving. Based on these circumstances, we are asking for a fund to pursue following 4 aims; Aim 1: Establish a system for online manuals. Aim 2: Multi-platform support: The current DtlStudio supports only Windows platform. We will port DtlStudlo to Linux, Unix, and Mac OSX platform. Aim 3: Introduction of advanced software management and open source: The functionality of DtiStudio is ever growing, which makes it important to introduce advanced software management system for version tracking and working environment for multiple developers. This also provides an environment for open source. Aim 4: Upgrade to integrate new technologies.